Breast cancer is the most frequently occurring cancer among US women. Largely due to improvements in screening and treatment, breast cancer mortality rates in the US have declined significantly since 1975. In combination with an aging population, the number of breast cancer survivors has grown and is projected to continue increasing. Currently, an estimated 2.7 million breast cancer survivors are alive in the US, and nearly 90% of the estimated 232,340 women diagnosed with breast cancer this year will be alive 5 years after diagnosis. Breast cancer survivors may experience short- and long-term adverse effects, including reduced quality of life, sexual, and cognitive functioning; and increased fatigue, depression, and vasomotor symptoms (VMS). Existing research has studied these outcomes following a cancer diagnosis, but to our knowledge, none has compared cancer survivors to appropriate controls, had lengthy pre-and post-diagnosis data, and examined multiple relevant outcomes over time in a single cohort with longitudinal data. The proposed research capitalizes on existing data from a multiethnic/racial cohort of 3302 women who were pre- and early peri-menopausal at baseline and have been followed through the menopausal transition in the Study of Women's Health Across the Nation (SWAN) with 15 visits over nearly 20 years. The proposed research will use innovative statistical techniques to provide a comprehensive view of the impact of breast cancer on a range of outcomes and begin to explore the role that inflammation plays in these outcomes. Specifically, we aim to: 1) compare women who develop incident breast cancer in the SWAN cohort to those who have not developed cancer to determine the impact of breast cancer diagnosis and treatment on symptoms (fatigue, depression, VMS, sleep problems), functioning (sexual, cognitive), and quality of life; 2) among women with breast cancer only, examine the impact of cancer treatment (chemotherapy, radiation), age at diagnosis, time since diagnosis, menopausal stage at diagnosis, and psychosocial factors on the above outcomes, as well as on newly acquired in-depth measures of fatigue, illness intrusiveness, and cancer-related quality of life, and consider outcomes jointly to identify different states or profiles of women; and 3) as an exploratory aim, we will compare breast cancer survivors and age-matched controls to examine the impact of cancer and/or treatment on hs-CRP, examining the time course of inflammation between the two groups and whether this inflammatory marker is associated with the impact of cancer on fatigue, depression, sleep, and/or cognition. The proposed research capitalizes on an existing comparison group within the SWAN cohort, detailed pre-and post-diagnostic information already available in SWAN, and use of analytic approaches, such as latent growth analysis to identify different trajectories of outcomes. Our results will also further advance our knowledge of the relationships between inflammation and symptoms of fatigue, depression, sleep, and cognition. The proposed work will allow for improved risk profiles to accelerate interventions specific to cancer survivors.